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PRAC confirms its previous conclusion on risk of inhibitor development with factor VIII medicines

News

01/09/2017

No clear and consistent evidence
exists of a difference in risk between plasma-derived and recombinant factor
VIII medicines

Following a re-examination procedure,
EMA’s Pharmacovigilance Risk Assessment Committee (PRAC) has confirmed its previous
conclusion of May 2017 that there is no clear and consistent evidence of a
difference in the incidence of inhibitor development between the two classes of
factor VIII medicines: those derived from plasma and those made by recombinant
DNA technology.

Factor VIII is needed for blood to
clot normally and is lacking in patients with haemophilia A. Factor VIII medicines
replace the missing factor VIII and help control and prevent bleeding. However
the body may develop inhibitors as a reaction to these medicines, particularly
in patients starting treatment for the first time. This can block the
medicines’ effect, so bleeding is no longer controlled.

Due to the
different characteristics of individual products within the two classes, the
PRAC reaffirmed that the risk of inhibitor development
should be evaluated individually for each medicine, regardless of class. The risk for each product will continue
to be assessed as more evidence becomes available.

To reflect the evidence currently
available, the PRAC confirmed its recommendations that the prescribing
information should be updated to include, as appropriate, inhibitor development
as a very common side effect in previously untreated patients, and as an
uncommon side effect in previously treated patients. The warning on inhibitor
development should be amended to highlight that low levels of inhibitors pose
less risk of severe bleeding than high levels.

The PRAC’s final recommendation will
now be sent to EMA’s Committee for Medicinal Products for Human Use (CHMP) for
the adoption of EMA’s opinion. Further details and information for patients and
healthcare professionals will be published at that time.

More about the medicine

The review covers all medicines
containing human factor VIII authorised in the European Union. Factor VIII is a
clotting protein and these medicines are used to temporarily increase levels of
this protein in patients with haemophilia A, helping to prevent and control
bleeding.

Human plasma-derived factor VIII
medicines are extracted from blood plasma. Recombinant factor VIII products, on
the other hand, are produced by a method known as ‘recombinant DNA technology’:
they are made by cells into which a gene (DNA) has been introduced to enable
the cells to produce factor VIII.

The review was carried out by the
Pharmacovigilance Risk Assessment Committee (PRAC), the Committee responsible
for the evaluation of safety issues for human medicines, which made a set of
recommendations in May 2017.

Following
a request from a company involved in the review, the PRAC re-examined its
initial recommendation. The PRAC’s final recommendations
will now be sent to the Committee for Medicinal Products for Human Use (CHMP),
responsible for questions concerning medicines for human use, which will adopt
the Agency’s opinion.

The final stage of the review
procedure is the adoption by the European Commission of a legally binding
decision applicable in all EU Member States.